汽车构造英文版Word格式文档下载.docx

汽车构造英文版Word格式文档下载.docx

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Transmissionsystems―conveysthedrivetothewheels.Themaincomponentsareclutch,gearbox,driveshaft,finaldrive,anddifferential.

Suspension―absorbstheroadshocks.

Steering―controlsthedirectionofthemovement.

Brake―slowsdownthevehicle.

1.5 

Electrical 

Equipment

Theelectricalsystemsupplieselectricityfortheignition,horn,lights,heater,andstarter.Theelectricitylevelismaintainedbyachargingcircuit.Thiscircuitconsistsofthebattery,alternator（orgenerator）.Thebatterystoreselectricity.Thealternatorchangestheengine'

smechanicalenergyintoelectricalenergyandrechargesthebattery.

NewWords

Principalcomponent 

主要部件

category 

种类，类型

body 

车身

chassis 

底盘

layout 

布置

powerunit 

动力装置

internalcombustionengine 

内燃机

cylinder 

汽缸

gasoline 

汽油

spark 

火花

ignition 

点燃，点火

diesel 

柴油机

compression 

压缩

shaft 

轴

transmission 

传动系

sheetmetal 

金属板

shell 

外壳

hood 

（发动机）罩

trunkdeck 

行李舱盖

cargo 

货物

styling 

样式

assembly 

总成，装配

suspension 

悬挂，悬置

shock 

冲击

steering 

转向，操纵

brake 

刹车，制动器

clutch 

离合器

gearbox 

变速器

driveshaft 

传动轴

finaldrive 

主减速器，后桥

differential 

差速器

slowdown 

（使）慢下来，减速

horn 

喇叭

starter 

起动机

charge 

充电

alternator 

交流发电机

ReviewQuestions

1.Listthemainpartsofanautomobile?

2.Whatarethecommontypesofavehicleaccordingtobodystyling?

3.Whichsystemsdoesachassisincludeandwhatarethemainfunctionsofthechassis?

4.Whyaresuspensionsystemsusedonvehicles?

CHAPTER2INTERNALCOMBUSTIONENGINE

2.1principleofoperation

2.1.1Engineandpower

Engineisusedtoproducepower.Thechemicalenergyinfuelisconvertedtoheatbytheburningofthefuelatacontrolledrate.Thisprocessiscalledcombustion.Ifenginecombustionoccurswiththepowerchamber.,theengineiscalledinternalcombustionengine.Ifcombustiontakesplaceoutsidethecylinder,theengineiscalledanexternalcombustionengine.

Engineusedinautomobilesareinternalcombustionheatengines.Heatenergyreleasedinthecombustionchamberraisesthetemperatureofthecombustiongaseswiththechamber.Theincreaseingastemperaturecausesthepressureofthegasestoincrease.Thepressuredevelopedwithinthecombustionchamberisappliedtotheheadofapistontoproduceausablemechanicalforce,whichisthenconvertedintousefulmechanicalpower.

2.1.2EngineTerms

Linkingthepistonbyaconnectingrodtoacrankshaftcausesthegastorotatetheshaftthroughhalfaturn.Thepowerstroke“usesup”thegas,someansmustbeprovidedtoexpeltheburntgasandrechargethecylinderwithafreshpetrol-airmixture:

thiscontrolofgasmovementisthedutyofthevalves;

aninletvalveallowsthenewmixturetoenterattherighttimeandanexhaustvalveletsouttheburntgasafterthegashasdoneitsjob.Enginetermsare:

TDC（TopDeadCenter）:

thepositionofthecrankandpistonwhenthepistonisfartherawayfromthecrankshaft.

BDC（BottomDeadCenter）:

thepositionofthecrankandpistonwhenthepistonisnearesttothecrankshaft.

Stroke:

thedistancebetweenBDCandTDC;

strokeiscontrolledbythecrankshaft.

Bore:

theinternaldiameterofthecylinder.

Sweptvolume:

thevolumebetweenTDCandBDC.

Enginecapacity:

thisisthesweptvolumeofallthecylindere.g.afour-strokehavingacapacityoftwoliters（2000cm）hasacylindersweptvolumeof50cm.

Clearancevolume:

thevolumeofthespaceabovethepistonwhenitisatTDC.

Compressionratio=（sweptvol+clearancevol）\（clearancevol）

Two-stroke:

apowerstrokeeveryrevolutionofthecrank.

Four-stroke:

apowerstrokeeveryotherrevolutionofthecrank..

2.1.3TheFour-strokeSpark-ignitionEngineCycle

Thespark-ignitionengineisaninternal-combustionenginewithexternallysuppliedinignition,whichconvertstheenergycontainedinthefueltokineticenergy.

Thecycleofoperationsisspreadoverfourpistonstrokes.Tocompletethefullcycleittakestworevolutionsofthecrankshaft.

Theoperatingstrokesare:

Thisstrokeintroducesamixtureofatomizedgasolineandairintothecylinder.Thestrokestartswhenthepistonmovesdownwardfromapositionnearthetopofthecylinder.Asthepistonmovesdownward,avacuum,orlow-pressurearea,iscreated.

Duringtheintakestroke,oneoftheportsisopenedbymovingtheinletvalve.Theexhaustvalveremainstightlyclosed.

Compressionstroke

Asthepistonmovesupwardtocompressthefuelmixturetrappedinthecylinder,thevalvesareclosedtightly.Thiscompressionactionheatstheair/fuelmixtureslightlyandconfinesitwithinasmallareacalledthecombustionchamber.

Powerstroke

Justbeforethepistonreachesthetopofitscompressionstroke,anelectricalsparkisintroducedfromasparkplugscrewedintothecylinderhead.

Thesparkignitesthecompressed,heatedmixtureoffuelandairinthecombustionchambertocauserapidburning.Theburningfuelproducesintenseheatthatcausesrapidexpansionofthegasescompressedwithinthecylinder.Thispressureforcesthepistondownward.Thedownwardstroketurnsthecrankshaftwithgreatforce.

Exhauststroke

Justbeforethebottomofthepowerstroke,theexhaustvalveopens.Thisallowsthepiston,asitmovesupward,topushthehot,burnedgasesoutthroughtheopenexhaustvalve.

Then,justbeforethepistonreachesitshighestpoint,theexhaustvalveclosesandtheinletvalveopens.Asthepistonreachesthehighestpointinthecylinder,knownasTDC,itstartsbackdownagain.Thus,onecycleendsandanotherbeginsimmediately.

2.1.4EngineOverallMechanics

Theenginehashundredsofotherparts.Themajorpartsofengineareengineblock,engineheads,pistons,connectingrods,crankshaftandvalves.Theotherpartsarejoinedtomakesystems.Thesesystemsarethefuelsystem,intakesystem,ignitionsystem,coolingsystem,lubricationsystemandexhaustsystem.Eachofthesesystemshasadefinitefunction.Thesesystemswilldiscussedindetaillater.

NEWWORD

Piston活塞

Connectingrod连杆

Crankshaft曲轴

Powerstoke活塞行程

Expel排出

Valve气阀

inlet（intake）valve进气阀

exhaustvalve排气阀

term术语

TDC上止点

BDC下止点

Bore缸径

sweptvolume有效容积

enginecapacity发动机排量

clearancevolume余隙容积,燃烧室容积

compressionratio压缩比

revolution旋转,转数

everyother每隔一个

cycle循环

spreadover分布,遍及

intakestroke进气行程

compressionstroke压缩行程

knock敲缸,敲打

exhauststroke排气行程

engineblock发动机缸体

lubrication润滑

2.2EngineBlockandCylinderHead

2.2.1 

EngineBlock

Theengineblockisthebasicframeoftheengine.Allotherenginepartseitherfitinsideitorfastentoit.Itholdsthecylinders,waterjackets,andoilgalleries.Theengineblockalsoholdsthecrankshaft,whichfastenstothebottomoftheblock.Thecamshaftalsofitsinsidetheblock,exceptonoverhead-camengines（OHC）.Inmostcars,thisblockismadeofgrayiron,oranalloy（mixture）ofgrayironandothermetals,suchasnickelorchromium.Engineblocksarecastings.

Someengineblocks,especiallythoseinsmallercars,aremadeofcastaluminum.Thismetalismuchlighterthaniron.However,ironwearsbetterthanaluminum.Therefore,thecylindersinmostaluminumenginesarelinedwithironorsteelsleeves.Thesesleevesarecalledcylindersleeves.Someengineblocksaremadeentirelyofaluminum.

2.2.2 

CylinderHead

Thecylinderheadfastenstothetopoftheblock,justasarooffitsoverahouse.Theundersideformsthecombustionchamberwiththetopofthepiston.Themostcommoncylinderheadtypesarethehemi,wedge,andsemi-hemi.Allthreeofthesetermsrefertotheshapeoftheengine'

scombustionchamber.Thecylinderheadcarriesthevalves,valvespringsandtherockersontherockershaft,thispartofthevalvegearbeingworkedbythepush-rods.Sometimesthecamshaftisfitteddirectlyintothecylinderheadandoperatesonthevalveswithoutrockers.Thisiscalledanoverheadcamshaftarrangement.Likethecylinderblock,theheadismadefromeithercastironoraluminumalloy.

2.2.3 

Gasket

Thecylinderheadisattachedtotheblockwithhigh-tensilesteelstuds.Thejointbetweentheblockandtheheadmustbegas-tightsothatnoneoftheburningmixturecanescape.Thisisachievedbyusingcylinderheadgasket.Thisisasandwichgasket,i.e.asheetofasbestosbetweentwosheetsofcopper,boththesematerialsbeingabletowithstandthehightemperatureandpressureswithintheengine